Introducing MRI: Chemical Shift (28 of 56)

  Рет қаралды 53,236

Albert Einstein College of Medicine

Albert Einstein College of Medicine

Күн бұрын

Пікірлер: 16
@MonaLisa-sv7cm
@MonaLisa-sv7cm 8 жыл бұрын
Thank you Dr. Lipton. Hello from Nepal
@saeedak2669
@saeedak2669 2 жыл бұрын
why did the pancreas and the blood in aorta and IVC had increased signal in outphased image comparing to inphased one?
@alehsudakou1277
@alehsudakou1277 8 жыл бұрын
Best explanation! very clear!
@ksawery6568
@ksawery6568 8 жыл бұрын
Great lectures, thank you!
@carcaperu4041
@carcaperu4041 6 жыл бұрын
12:00 Shouldn't it be shifted by two positions (224/100)?
@Thaifunn1
@Thaifunn1 6 жыл бұрын
yes
@elmitte
@elmitte 3 жыл бұрын
Shouldn't the frequency encoding direction be opposite of what is depicted during 9'-17'' ? [given fat spinning slower than water, it will be misregistered in lower frequency (shifted the opposite direction to the frequency encoding). In a left to right frequency encoding we will have higher gradient (and hence higher frequencies) on the right side]
@connorgemmell5789
@connorgemmell5789 3 жыл бұрын
Yes, in his diagram of the water/olive oil example he misdrew the chem shift in the opposite direction. Fat signal should be shifted against the frequency encoding direction, so really what should happen in that diagram is a bright stripe on the rightward border of the water, and a dark stripe on the rightward border of the oil. Similarly, in his example image of the psoas muscles, the frequency encoding direction is in the opposite direction of how he labelled the images. We see fat signal is shifted to the right on the image (patient's left), which means the frequency encoding gradient is from right-to-left on the image (or, left-to-right for the patient).
@Narender0singh
@Narender0singh 10 ай бұрын
thanks man, i wasted 15 minutes because of that
@lester_ernesto
@lester_ernesto 8 жыл бұрын
Great explanation !! BTW, does anyone knows what the actual Bandwidths are in the example prof. Lipton presents in minute 24:00? (H.D shoulder comparison imaging) The slide was cut short in the lower part. Thanks
@spdn
@spdn 7 жыл бұрын
no idea. I thought it is labeled wrong, the left should be "WFS = 3 pixels = 1.5mm" instead. also the conclusion at 24:20 should be "higher bandwith is both giving us a decrease in signal-to-noise as well as decreasing the amount of chemical shift effects"
@connorgemmell5789
@connorgemmell5789 3 жыл бұрын
The numbers appear to be BW of 57 kHz in the right image, and about 19 kHz (19.3 I believe) in the left image. If we divide 57 kHz into a 256-pixel width in the frequency-encoding direction, that means each pixel is 57 kHz / 256 = 222 Hz wide. Given a chem shift of 224 Hz at 1.5T, that results in a chem shift spatially of almost exactly one pixel, just as is reported. Conversely, with a 19 kHz bandwidth, each pixel is 19 kHZ / 256 = 74 Hz wide, so a 224 Hz shift translates to 3 pixels spatially. Also, I agree with spdn. The left image should be labelled WFS of 3 pixels, 1.5mm. And he misspoke at 24:20, the higher bandwidth in the right image results in a tradeoff, decreased chem shift effect but reduced SNR.
@shekharkalia5856
@shekharkalia5856 7 жыл бұрын
AMAZING!
@juancalle9213
@juancalle9213 3 жыл бұрын
Great!!
@amitkumaryadav9228
@amitkumaryadav9228 2 жыл бұрын
i was searching so hard for someone to explain chemical shift and india ink artefacts. this lecture made it sound so easy. cleared all my doubts. Thank you so much...
@praveenr5403
@praveenr5403 7 жыл бұрын
thanks for the wonderful explanations
Introducing MRI: Longitudinal Magnetization Relaxation (11 of 56)
20:54
Albert Einstein College of Medicine
Рет қаралды 80 М.
Introducing MRI: Perfusion Imaging (53 of 56)
26:55
Albert Einstein College of Medicine
Рет қаралды 60 М.
From Small To Giant Pop Corn #katebrush #funny #shorts
00:17
Kate Brush
Рет қаралды 69 МЛН
iPhone or Chocolate??
00:16
Hungry FAM
Рет қаралды 38 МЛН
Chemical Shift Artifact MRI  | MRI Physics Course #14
21:21
Radiology Tutorials
Рет қаралды 15 М.
Introducing MRI: MR Safety (47 of 56)
55:11
Albert Einstein College of Medicine
Рет қаралды 38 М.
fat suppression webinar replay.mp4
33:41
GE HealthCare
Рет қаралды 2,4 М.
MRI ARTIFACTS | CHEMICAL SHIFT | ALIASING | MOIRE FRINGE | ZIPPER |
26:58
Indian Radiologist
Рет қаралды 21 М.
Isolation tutorial: Neuroradiology with Frank Gaillard
50:50
Radiology Channel
Рет қаралды 82 М.
Introducing MRI: MR Imaging of Hemorrhage (52 of 56)
28:11
Albert Einstein College of Medicine
Рет қаралды 45 М.
Metal Artifact Reduction Techniques - MR Parameters
10:44
Everything MRI
Рет қаралды 2,9 М.
Introducing MRI: K-space: Features and Tricks (24 of 56)
35:01
Albert Einstein College of Medicine
Рет қаралды 71 М.
Introducing MRI: Slice Selection (21 of 56)
39:26
Albert Einstein College of Medicine
Рет қаралды 98 М.
From Small To Giant Pop Corn #katebrush #funny #shorts
00:17
Kate Brush
Рет қаралды 69 МЛН